Image Processing Device

Abstract

To provide an image processing device capable of removing a horizontal streak that may show when a document is scanned and made into a file.SOLUTION: An image processing device includes: an image processing unit configured to generate smoothing image data obtained by applying smoothing to image data, and save, as an image file, non-smoothing image data in which smoothing is not applied to the image data when a difference between the non-smoothing image data and the smoothing image data is equal to or greater than a threshold value, and the smoothing image data when the difference is smaller than the threshold value; and a storage unit configured to save the image file.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] FIELD An embodiment of the present invention relates to an image processing device. [Background technology]

[0002] 2. Description of the Related Art There are image reading devices and image forming devices that are equipped with an ADF (Auto Document Feeder), which is convenient for scanning documents. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-237874 Summary of the Invention [Problem to be solved by the invention]

[0004] Scanning documents while feeding them through an ADF (Auto Document Feeder) is convenient, but when various image processing techniques such as smoothing are applied to create a PDF image file, faint horizontal lines that were not visible in the image before the processing may appear in the image after the processing. When converting documents to PDF, it is necessary to pay attention to such noise, which can be troublesome. The problem that this invention aims to solve is to provide an image processing device that can remove horizontal lines that may appear when scanning documents and creating a file. [Means for solving the problem]

[0005] The image processing device of the embodiment generates smoothed image data by smoothing image data, and generates non-smoothed image data by not smoothing image data, and smoothed image data. Concentration If the difference is greater than or equal to a threshold, the unsmoothed image data is ConcentrationThe image processing unit stores the smoothed image data as an image file if the difference is smaller than a threshold value, and the storage unit stores the image file.

[0006] In addition, the image processing device of the embodiment converts image data into a non-PDF image file that is not in PDF format, Image processing was applied PDF image files are in PDF format, non-PDF image files are rasterized images, and PDF image files are rasterized images. Concentration If the difference is greater than or equal to the threshold, the non-PDF image file is Concentration The system includes an image processing unit that allows user access to the PDF image file if the difference is less than a threshold, and a storage unit in which the non-PDF image file and the PDF image file are stored. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is an external view showing an example of the overall configuration of an image forming apparatus 1 according to an embodiment. [Figure 2] 1 is a hardware block diagram showing a hardware configuration of an image forming apparatus 1 according to an embodiment. [Figure 3] FIG. 4 illustrates an example of the internal configuration of a printer 400. [Figure 4] 10 is a flowchart showing the flow of processing according to the first embodiment for scanning a sheet to obtain image data and creating a file. [Figure 5] 10 is a flowchart showing the flow of processing according to a second embodiment for scanning a sheet to obtain image data and creating a file. DETAILED DESCRIPTION OF THE INVENTION

[0008] FIG. 1 is an external view showing an example of the overall configuration of an image forming apparatus 1 as an embodiment of an image processing apparatus. FIG. 2 is a hardware block diagram showing the hardware configuration of the image forming apparatus 1 of the embodiment. First, explanation will be given mainly using FIG. 1. The image forming apparatus 1 is, for example, a multifunction peripheral. The image forming apparatus 1 includes a main control unit 100, a sheet storage unit 140, an operation panel 200, a scanner 300, and a printer 400. The image forming apparatus 1 forms an image on a sheet using a developer. The developer is, for example, toner. In the following explanation, the developer is described as toner. The sheet is, for example, paper or label paper. The sheet may be any material on whose surface the image forming apparatus 1 can form an image.

[0009] The operation panel 200 includes one or more operation keys 202 and a display 203. The operation panel 200 accepts operations by the user. The operation panel 200 outputs a signal to the main control unit 100 in accordance with the operation performed by the user.

[0010] The display 203 is an image display device such as a liquid crystal display, an organic EL (Electro Luminescence) display, etc. The display 203 displays various information related to the image forming apparatus 1.

[0011] The printer 400 forms an image on a sheet based on image data generated by the scanner 300 or image data received via a network. The printer 400 forms an image using toner. The sheet on which the image is formed may be a sheet stored in the sheet storage unit 140 or a sheet that is manually inserted. In the following description, forming an image is also referred to as printing an image.

[0012] The sheet storage section 140 stores sheets to be used for image formation in the printer 400 .

[0013] The scanner 300 reads the image of the object to be read as light and dark of light. The scanner 300 saves the read image data. The saved image data may be transmitted to another information processing device via a network. The image represented by the saved image data may be formed on a sheet by the printer 400.

[0014] Next, explanation will be made mainly using Fig. 2. In Fig. 2, image forming apparatus 1 has a main control unit 100, an operation panel 200, a scanner 300, and a printer 400. Image forming apparatus 1 includes a main CPU 101 in main control unit 100, a panel CPU 201 in operation panel 200, a scanner CPU 301 in scanner 300, and a printer CPU 401 in printer 400.

[0015] The main control unit 100 includes a main CPU 101, a ROM 102, a RAM 103, an NVRAM 104, a network controller 105, an HDD 106, a modem 107, a page memory 109, a PM (page memory) control unit 110, and an image processing unit 111.

[0016] The main CPU 101 controls the overall operation of the image forming apparatus 1. The ROM 102 stores data necessary for control such as a control program. The RAM 103 temporarily stores data. The NVRAM 104 is a non-volatile memory.

[0017] The network controller 105 connects the image forming apparatus 1 to a network. The image forming apparatus 1 communicates with external devices such as a server or a PC (Personal Computer) via the network controller 105. The HDD 106 stores data such as images used in image formation and images read by the scanner 300. The HDD 106 is an example of a storage unit. Of the image data stored in the HDD 106, the header of the image data read by the scanner 300 contains information indicating the reading resolution at the time of reading and the recording resolution saved in the HDD 106. The modem 107 connects the image forming apparatus 1 to a telephone line.

[0018] The page memory 109 stores image data for multiple pages, one page at a time. The page memory control unit 110 controls the page memory 109. The image processing unit 111 performs image processing on the image data. Specific examples of image processing include color conversion processing, range correction processing, sharpness adjustment processing, gamma correction / halftone processing, and pulse width modulation (PWM) processing. The image processing unit 111 may be implemented using hardware such as an ASIC (Application Specific Integrated Circuit), or may be implemented using software.

[0019] The operation panel 200 has a panel CPU 201, operation keys 202, and a display 203. The panel CPU 201 controls the operation panel 200. The panel CPU 201 is connected to the main CPU 101 via a bus. When the panel CPU 201 receives a display instruction from the main CPU, it controls the screen of the display 203 in accordance with the received instruction. When the panel CPU 201 receives a numerical value, a process to be executed, or setting information from the operation keys 202, it outputs data indicating these to the main CPU 101. The operation keys 202 are an input device for inputting a process to be executed, setting information, numerical values, etc. Specific examples of information received by the operation keys 202 include various instructions and settings such as the type of sheet on which an image is to be formed (size and orientation) and the magnification of image formation. The display 203 is a display device such as a liquid crystal display or an organic EL display. The display 203 may be configured as a touch panel.

[0020] The scanner 300 includes a scanner CPU 301, an image correction unit 302, a reading control unit 303, a CCD (Charge Coupled Device) 304, and an ADF 305. The scanner CPU 301 controls the scanner 300. The image correction unit 302 includes, for example, an A / D conversion circuit, a shading correction circuit, and a line memory. The A / D conversion circuit converts the R, G, and B analog signals output from the CCD 304 into digital signals. The ADF 305 is an automatic document feeder. The ADF 305 takes a sheet placed by a user into a conveyance path in a conveyance direction corresponding to the orientation of the sheet. The ADF 305 conveys the sheet by rotating conveyance rollers in the conveyance path, and the CCD 304 reads the image on the sheet being conveyed. The CCD 304 can also read the image on a sheet placed on the scanner 300.

[0021] The printer 400 has a printer CPU 401, a laser driver 402, a transport control unit 403, and a control unit 404. The printer CPU 401 controls the printer 400. The laser driver 402 drives a laser to form an electrostatic latent image on a photosensitive member. The transport control unit 403 transports a sheet on which an image is to be formed. The control unit 404 controls devices such as the laser driver 402 to form an image on the sheet transported by the transport control unit 403.

[0022] Fig. 3 is a diagram showing an example of the internal configuration of the printer 400. In the example of Fig. 3, the printer 400 is a four-tandem type printer. However, the printer 400 does not have to be limited to a four-tandem type.

[0023] The printer 400 includes an image forming unit 10, a fixing unit 30, and a paper discharge unit 40. The image forming unit 10 includes an intermediate transfer body 11, developing devices 91 to 94, a plurality of primary transfer rollers 17 (17-1 to 17-4), a secondary transfer unit 18, and an exposure unit 19.

[0024] Intermediate transfer body 11 may be configured using, for example, an endless belt. Intermediate transfer body 11 is rotated in the direction of arrow 1010 by a roller. In this embodiment, upstream and downstream are defined based on the direction in which intermediate transfer body 11 moves. Visible images generated by developing devices 91-94 are transferred onto the surface of intermediate transfer body 11.

[0025] The developing devices 91 to 94 each form a visible image using toners with different properties. For example, some of the developing devices may use toners of different colors. As toners of different colors, yellow (Y), magenta (M), cyan (C), and black (K) toners may be used. Some of the developing devices may use toners whose color disappears when exposed to an external stimulus (for example, heat). Some of the developing devices may use special toners, such as glossy toners or fluorescent toners.

[0026] In FIG. 3, developing device 91 is located most upstream of the four developing devices, and developing device 94 is located most downstream of the four developing devices.

[0027] Developing devices 91 to 94 have the same configuration but use different toner properties. Developing device 91 includes a developing unit 121, a photosensitive drum 131, a charger 141, a cleaning blade 151, and a developing drum 161. Developing device 92 includes a developing unit 122, a photosensitive drum 132, a charger 142, a cleaning blade 152, and a developing drum 162. Developing device 93 includes a developing unit 123, a photosensitive drum 133, a charger 143, a cleaning blade 153, and a developing drum 163. Developing device 94 includes a developing unit 124, a photosensitive drum 134, a charger 144, a cleaning blade 154, and a developing drum 164.

[0028] In the following description, when there is no need to distinguish between developing units 121, 122, 123, and 124, they will be referred to as developing units 12. The same applies to photosensitive drum 13, charger 14, cleaning blade 15, and developing drum 16.

[0029] The developing device will be described below using developing device 91 as an example. Developing device 91 includes a developing unit 121, a photosensitive drum 131, a charger 141, a cleaning blade 151, and a developing drum 161. Developing unit 121 contains toner and carrier. Developing unit 121 causes toner to adhere to photosensitive drum 131 by developing drum 161.

[0030] The photosensitive drum 131 has a photosensitive body (photosensitive area) on its outer circumferential surface. The photosensitive body is, for example, an organic photoconductor (OPC). The photosensitive drum 131 is exposed by the exposure unit 19, and an electrostatic latent image is formed on the surface. The charger 141 uniformly charges the surface of the photosensitive drum 131 .

[0031] The cleaning blade 151 is, for example, a plate-shaped member. The cleaning blade 151 is made of, for example, rubber such as urethane resin. The cleaning blade 151 removes toner adhering to the photosensitive drum 131.

[0032] Next, an outline of the operation of the developing device 91 will be described. The photosensitive drum 131 is charged to a predetermined potential by the charger 141. Next, light is irradiated onto the photosensitive drum 131 from the exposure unit 19. This changes the potential of the area of the photosensitive drum 131 irradiated with light. This change causes an electrostatic latent image to be formed on the surface of the photosensitive drum 131. The electrostatic latent image on the surface of the photosensitive drum 131 is developed by toner in the developing unit 121. That is, a visible image, which is an image developed by the toner, is formed on the surface of the photosensitive drum 131.

[0033] The primary transfer rollers 17 (17-1 to 17-4) transfer the visible images formed on the photosensitive drums by the developing devices 91 to 94 onto the intermediate transfer body 11. The secondary transfer unit 18 includes a secondary transfer roller 181 and a secondary transfer opposing roller 182. The secondary transfer unit 18 transfers the visible image formed on the intermediate transfer body 11 all at once onto a sheet on which an image is to be formed. The transfer by the secondary transfer unit 18 is achieved by, for example, a potential difference between the secondary transfer roller 181 and the secondary transfer opposing roller 182.

[0034] The exposure unit 19 forms an electrostatic latent image by irradiating light onto the photosensitive drums of the developing devices 91 to 94. The exposure unit 19 includes a light source such as a laser or a light emitting diode (LED). In this embodiment, the exposure unit 19 includes a laser and operates under the control of a laser driver 402.

[0035] The fixing unit 30 applies heat and pressure to the visible image transferred onto the sheet, thereby fixing the visible image onto the sheet. The paper discharge unit 40 discharges the sheet, on which the visible image has been fixed by the fixing unit 30, to the outside of the image forming apparatus 1.

[0036] When scanning a sheet and applying various image processing techniques such as smoothing to create a PDF image file, there are cases where horizontal lines that were not visible in the image before the processing are applied appear faintly in the image in the file after the processing is applied. The smoothing function and PDF specification version are thought to be one of the causes of horizontal lines.

[0037] A first embodiment for removing horizontal streaks will be described. Non-smoothed image data is generated by not smoothing the image data obtained by scanning the sheet, and smoothed image data is generated by smoothing the image data obtained by scanning the sheet.

[0038] A comparison is made between the unsmoothed image data and the smoothed image data. The comparison is, for example, a comparison of density. It compares whether the density differs by more than a threshold for each pixel, or whether the density differs by more than a threshold for each block of multiple pixels, or whether the average density of the entire image data differs by more than a threshold. The comparison is, for example, a comparison by image recognition, in which the presence or absence, position, shape, and orientation of objects such as lines and figures obtained by image recognition are compared to see if they differ by more than a threshold value.

[0039] If no significant difference is found as a result of comparing the non-smoothed image data with the smoothed image data, the smoothed image data is adopted as the data to be made into an image file. If a significant difference is found as a result of comparing the non-smoothed image data with the smoothed image data, the non-smoothed image data is used instead of the smoothed image data as the data to be created into the image file. The non-smoothed image data of pixels at positions where a significant difference is found and the smoothed image data of pixels at positions where no significant difference is found may be selectively adopted on a pixel-by-pixel basis. The non-smoothed image data of the block where a significant difference is found and the smoothed image data of the block where no significant difference is found may be selectively used on a pixel-by-pixel basis.

[0040] A part or all of the adopted image data is subjected to processing to reduce blurring of characters and adjustments such as contrast to create an image file. When processing to reduce blurring of characters and adjustments such as contrast to only a part of the adopted image data is performed and an image file is created, information indicating the location of that part may be included in the image file as text, an image, or metadata. When processing to reduce blurring of characters and adjustments such as contrast to only a part of the adopted image data is performed and an image file is created, information indicating the location of that part may be displayed on the display 203 of the operation panel 200.

[0041] A second embodiment for removing horizontal streaks will be described. Image data obtained by scanning the sheet is saved in a non-PDF image file that is not in PDF format and a PDF image file that is in PDF format.

[0042] A comparison is performed between a rasterized image of a non-PDF image file and a rasterized image of a PDF image file. The comparison may be, for example, a comparison of color density. The comparison may be, for example, a comparison by image recognition.

[0043] When comparing a rasterized image of a non-PDF image file with a rasterized image of a PDF image file, if no significant difference is found, the PDF image file will be used. When comparing an image obtained by rasterizing a non-PDF image file with an image obtained by rasterizing a PDF image file, if a significant difference is found, the non-PDF image file will be used instead of the PDF image file.

[0044] The user is allowed to access either the PDF image file or the non-PDF image file, whichever is adopted. For example, allowing the user to access the file that has been selected means displaying the file that has been selected, either a PDF image file or a non-PDF image file, as an option on the operation panel 200. Giving the user access to the adopted file means, for example, attaching the adopted file to an email to be sent in a so-called ScanToEmail operation. The files that were not adopted may be deleted, or the user may be allowed to access them in a manner different from that for accessing the files that were adopted.

[0045] It is preferable to display information indicating whether a PDF image file or a non-PDF image file has been adopted on the display 203 of the operation panel 200. Displaying information indicating whether a PDF image file or a non-PDF image file has been adopted means, for example, displaying a message such as "Since noise appears in the file image in PDF format, it will be saved as a file in XX format" when a non-PDF image file has been adopted.

[0046] A process to reduce blurring of text or an adjustment of contrast, etc. may be applied to part or all of the adopted image file. When a process to reduce blurring of text or an adjustment of contrast, etc. is applied to only part of the adopted image file, information indicating the location of that part may be included in the image file as an image or metadata. When a process to reduce blurring of text or an adjustment of contrast, etc. is applied to only part of the adopted image file, information indicating the location of that part may be displayed on the display 203 of the operation panel 200.

[0047] The above-described processing will be explained using a flowchart. FIG. 4 is a flowchart showing the flow of processing according to the first embodiment for scanning a sheet to obtain image data and creating a file. The scanner 300 performs a scan process (ACT 101). Image data obtained by the scan process is stored in the page memory 109. The image processing unit 111 performs image processing on the image data stored in the page memory 109, and stores the image data in the HDD 106 (ACT 102).

[0048] The image processing unit 111 generates smoothed image data by smoothing the non-smoothed image data, which is image data stored in the HDD 106, and stores the smoothed image data in the HDD 106 (ACT 103). The image processing unit 111 compares the non-smoothed image data with the smoothed image data (ACT 104). If the difference between the non-smoothed image data and the smoothed image data is smaller than the threshold value (ACT104: NO), the image processing unit 111 adopts the smoothed image data as data to be made into an image file (ACT105). If the difference between the non-smoothed image data and the smoothed image data is equal to or greater than the threshold value (ACT104: YES), the image processing unit 111 adopts the non-smoothed image data as data to be made into an image file (ACT106). The image processing unit 111 applies processing to the adopted image data to reduce blurring of characters and adjust contrast, etc., and stores the image data as an image file in the HDD 106 (ACT107), and then ends the processing. In the case of a copy process, the printer 400 may form an image on a sheet based on the image file stored in the HDD 106.

[0049] FIG. 5 is a flowchart showing the flow of processing according to the second embodiment for scanning a sheet to obtain image data and creating a file. The scanner 300 performs a scan process (ACT 201). Image data obtained by the scan process is stored in the page memory 109. The image processing unit 111 performs image processing on the image data stored in the page memory 109, and stores the processed image data in the HDD 106 as a non-PDF image file that is not in PDF format and a PDF image file that is in PDF format (ACT202).

[0050] The image processing unit 111 compares the non-PDF image file with the PDF image file (ACT203). If the difference between the non-PDF image file and the PDF image file is smaller than the threshold value (ACT203: NO), the image processing unit 111 adopts the PDF image file (ACT204). If the difference between the non-PDF image file and the PDF image file is equal to or greater than the threshold (ACT203: YES), the image processing unit 111 adopts the non-PDF image file instead of the PDF image file (ACT205).

[0051] The image processing unit 111 allows the user to access the file that has been adopted, either the PDF image file or the non-PDF image file (ACT 206). The main CPU 101 displays information indicating whether a PDF image file or a non-PDF image file has been adopted on the display 203 of the operation panel 200 (ACT 207), and ends the process.

[0052] In the above-described embodiment, the main CPU 101 and the image processing unit 111 may be implemented in the same processor. The above embodiment may be configured as an image processing apparatus that does not include the printer 400. The above embodiment may be configured to communicate with an image processing apparatus that does not include the scanner 300 via the network controller 105 of the image processing apparatus, and obtain image data obtained by the scanner 300 performing scanning processing.

[0053] The functions of the image processing device and image forming device described in the above-described embodiments may be implemented by a computer. In this case, a program for implementing the functions may be recorded on a computer-readable recording medium, and the program may be loaded into a computer system and executed. The term "computer system" as used herein includes hardware such as an operating system and peripheral devices. The term "computer-readable recording medium" refers to portable media such as flexible disks, optical magnetic disks, ROMs, and CD-ROMs, as well as storage devices such as hard disks built into a computer system. The term "computer-readable recording medium" may also include media that dynamically store programs for a short period of time, such as communication lines used when transmitting programs over a network such as the Internet or a telephone line, or media that store programs for a fixed period of time, such as volatile memory within a computer system serving as a server or client. The program may be a program that implements only a portion of the functions described above, or may be a program that can be implemented in combination with a program already stored in the computer system.

[0054] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, as well as within the scope of the invention described in the claims and their equivalents. [Explanation of symbols]

[0055] 1...image forming apparatus, 101...main CPU, 102...ROM, 103...RAM, 111...image processing unit, 300...scanner, 400...printer

Claims

1. smoothing the image data to generate smoothed image data; When the difference in density between the smoothed image data and non-smoothed image data, which is not subjected to smoothing on the image data, is equal to or greater than a threshold, the non-smoothed image data is saved as an image file, and when the difference is smaller than the threshold, the smoothed image data is saved as an image file. an image processing unit; a storage unit in which the image file is stored; An image processing device comprising:

2. 2. The image processing apparatus according to claim 1, further comprising a scanner for scanning a sheet to obtain the image data.

3. The image processing device according to claim 1 , wherein the image processing unit applies image processing to the non-smoothed image data when the difference is equal to or greater than the threshold value, and applies image processing to the smoothed image data when the difference is less than the threshold value, and saves the results as the image file.

4. 2. The image processing apparatus according to claim 1, further comprising a printer for forming an image on a sheet based on the stored image file.

5. The image data is saved as a non-PDF image file that is not in PDF format and a PDF image file that is in PDF format after image processing, When a difference in density between the rasterized image of the non-PDF image file and the rasterized image of the PDF image file is equal to or greater than a threshold, the user is allowed to access the non-PDF image file, and when the difference is less than the threshold, the user is allowed to access the PDF image file. an image processing unit; a storage unit in which the non-PDF image file and the PDF image file are stored; An image processing device comprising:

Images